Molecular analysis of the ovine cystic fibrosis transmembrane conductance regulator gene.

There is a need for a large-animal model to investigate the etiology and biology of cystic fibrosis (CF) lung disease and to study potential therapies. The development and electrophysiology of the sheep airway have been shown to exhibit close functional parallels with the human airway, particularly with respect to the respiratory epithelium. We have cloned and sequenced the ovine cystic fibrosis transmembrane conductance regulator (CFTR) cDNA. It shows a high degree of conservation at the DNA coding and predicted polypeptide levels with human CFTR: at the nucleic acid level there is a 90% conservation (compared with 80% between human and mouse CFTR cDNA); at the polypeptide level, the degree of similarity is 95% (compared with 88% between human and mouse). Northern blot analysis and reverse transcription-PCR have shown that the patterns of expression of the ovine CFTR gene are very similar to those seen in humans. Further, the developmental expression of CFTR in the sheep is equivalent to that observed in humans. Thus, overall a CF sheep should show lung pathology similar to that of humans with CF. IMAGES:

目前亟需构建大型动物模型，以探究囊性纤维化（cystic fibrosis, CF）肺部疾病的病因学与发病机制，并研究潜在治疗方案。已有研究表明，绵羊气道的发育过程与电生理特性与人类气道存在高度相似的功能同源性，尤其在呼吸上皮组织层面表现尤为显著。我们已完成绵羊囊性纤维化跨膜传导调节因子（cystic fibrosis transmembrane conductance regulator, CFTR）的互补脱氧核糖核酸（complementary deoxyribonucleic acid, cDNA）克隆与测序工作。该序列与人类CFTR在DNA编码区及预测多肽链水平上均具有高度保守性：在核酸层面，二者同源性达90%（人类与小鼠CFTR cDNA的同源性仅为80%）；在多肽链层面，序列相似性达95%（人类与小鼠CFTR的相似性为88%）。经Northern印迹杂交与逆转录聚合酶链式反应检测，绵羊CFTR基因的表达谱与人类CFTR高度相似。此外，绵羊体内CFTR的发育性表达模式与人类完全一致。综上，囊性纤维化绵羊模型的肺部病理表型应与人类CF患者高度相似。图像：